A new product is described characterized by its qualities as an absorbent of undesirable scents present in the air and capable of simultaneously acting as a carrier of fragrances, aromas and other active ingredients, which are released, gradually by the carrier to the air around it. The combination of both factors, characterized by the composition of matter ability to absorb undesirable scents and release fragrances or other active ingredients, simultaneously and independently. The processes for obtaining this product is also described.
The search by mankind for absorption of unpleasant aromas and scents in the air that we breathe is as old as civilization. The earliest documents come from the Egyptians that used substances like charcoal, to absorb from the air the scent of the cadavers in the mummification process.
Over the centuries these processes of purification for breathable air evolved in their technique, particularly at the beginning of the XX century due to the advent of toxic gases for military purposes. This evolution consisting in the filtration of breathable air has progressed to satisfy military and industrial necessities. Quick advances in the state of the art where made during the second half of the XX century, to improve the quality of the air in closed spaces, due to the contaminants in the air, generated by industry, transportation and in general by modern human activities. These filtration and purification systems in general are expensive and active in nature, requiring energy to circulate the air for its filtration.
On the other hand the evolution of passive systems has been slow and not as effective as that of the active systems. Passive systems do not require energy to absorb scents; fans or forced air through filters are not necessary to absorb gases or undesirable substances in the air, Passive systems are characterized to be substances or products that exposed to the environment, absorb, adsorb (accumulation on the surface) or react chemically to eliminate undesirable scents, gases or particles from the air.
The necessity to counteract or to eliminate, effectively and economically, the undesirable odors in the air has increased along with population growth, especially in urban concentrations since this is where the largest amount of pollutants and substances that bother human smell are generated. Examples of patents addressing this problem, are U.S. Pat. Nos. 5,944,704; 5,932,495; 5,932,147; 5,891,508; 5,861,147; 5,856,248; 5,807,364; 5,782,409; 5,733,272; 5,714,137 and the 5,593,670.
Examples common to the necessity of counteracting these polluting agents that cause bad odors are: the elimination of the aroma of tobacco smoke and its smell that impregnates closed spaces, such as houses, offices and automobiles. The malodor of garbage in kitchens, houses and buildings. The necessity to absorb or to neutralize scents during storage of foods, ranging from domestic to commercial and industrial refrigerators. The previous examples are just a small sample of the dynamic and ever more complex universe of human beings and pets, cohabiting and using progressively more consumer goods in continuously reducing spaces.
In the combat of malodor scents, the most common and oldest is the one characterized by the use of substances that contain perfumes to mask scents. The masking of scents is the concealment of one smell by another, usually a malodor. However the preferences for different aromas vary according to the individual and require relatively large amounts of perfume to counteract smelly malodor aromas.
Other forms of controlling malodor are, for example, the use of chemical substances. These processes are known in the state of the art as degradation by oxidation, where oxidizing agents such as: Chlorine bleach, Sodium hypochlorite, Chlorine Dioxide, and Potassium Permanganate are used. Other forms use degradation processes for reduction of malodor, these use active ingredients such as, Sodium Bisulfate to reduce malodor. These substances can be dangerous and aggressive for humans if used in direct form or exposed to the environment, they may also be harmful if in direct contact to cloths and many different surface materials.
Another method for the control of malodor is the use of active ingredients designed to react with smelly or malodor substances, by using specific chemical groups. Examples of these substances are the biguanid polymers that are mingled with organic compounds that contain atoms N and/or S, as well as the esters of fatty alcohol""s of Methyl Methacrylic that react with thiols, ammines and aldehydes. Their benefits are limited since they only react with certain very specific types of malodor.
Other types of well-known compounds are deodorants, in the state of the art these are antibacterial and fungicidal which destroy microorganisms that produce malodor. These compounds, typical in formulations of products for personal hygiene, are not effective in combating smelly substances that have already been generated and that do not come from sources like tobacco smoke or food.
Other forms of eliminating undesirable aromas from the air, are achieved, using absorbent substances or products. Malodor particles or compounds stick to their molecular structure; these chemical compositions are the cause of malodor. Other absorbent agents are characterized by admitting and retaining the malodor molecule inside their molecular structure. Among the more common absorbent agents are charcoal, alkaline compounds such as sodium bicarbonate, aluminum silicates and Zeolite. Some chemical substances are also absorbents, such as: Ciclodextrine whose intermolecular cavities admit small molecules of malodor. However, Ciclodextrin, especially when formulated in a watery solution, is considered fertile ground for microorganisms, given their important glucose content.
Finally it is necessary to consider that conceptually there are two forms of achieving reduction or elimination of malodor. The first is called a passive system, meaning that upon exposure to the environment, the active ingredient or the absorbent agent eliminates malodor scents from the surrounding air by contact. The second is an active system that achieves effectiveness by utilizing a mechanical devise. Most common are forced air systems that circulate air that in combination with absorbent or active ingredients, filter, absorb, perfume, or react chemically with malodor substances.
The functional objective of this invention, is that this composition of matter gathers three simultaneous qualities: 1) absorbs undesirable scents from the air 2) simultaneously releases into the air different types of active ingredients, usually but not limited to pleasant aromas. 3) Operates efficiently and economically by being a passive agent that does not require use of energy and it""s associated operating cost.
Additionally it is necessary to contemplate other factors that are concurrent in the present invention and that are part of the new product, object of this invention in it""s functional aspects:
First; Current tendencies prefer the use of organic and biodegradable materials, such is the case of this absorbent carrier that while absorbing malodors and releasing active ingredients into it""s surrounding, is compatible with the environment and easily disposable and recyclable in nature.
Second; Covered under the concept of aromas we find pleasent smelling substances perceivable to the human sense of smell, as well as other substances that without being significantly disagreeable to humans may be used as repellents or attractants for other species. The composition of matter object of this invention can also be used as a carrier for repellents or attractants to species like insects, microorganisms, reptiles, mammals, etc.
The concept of the new product derived from the present invention, is enlarged in its range of applications. For example, uses in agriculture, home and industry are possible by combining its qualities to absorb malodor and gradually release an aromatic substance to repel plagues of insects like cockroaches in kitchens or mosquitoes as well as other agricultural crop damaging insects. Good results are obtained by combining a substance like Nepetalactone, known for its qualities as a repellent of cockroaches or garlic known for its qualities as a repellent for garden or agriculture damaging insects, with this absorbent carrier. Additionally the absorbent carrier has the capacity to gradually release these forms of repellent aromas providing for a long lasting product; malodor, if present is also absorbed. Inversely, attractant substances can be used, being of particularly useful application for household pets, for example, the use of an attractant aroma or fragrance in the production of cat litter.
Third; the absorbent agent can be combined with other chemical substances whose properties allow them to react chemically with aromas present in the air. This includes the use of substances not perceived by human smell. Such as oxidizing agents or reducers that can help neutralize the concurrence of diverse aromas, like those present in a refrigerator; Simultaneously the aroma absorption capacity of the carrier comes into effect resulting in a refrigerator that doesn""t smell.
Another example for the use of the composition of matter subject of this invention, is its use for medicinal and therapeutic use. As is the case of aromatherapy, where the carrier releases into the air of a room, automobile, or office, aromas of medicinal type in accordance to the results a user is trying to achieve, for example: Aroma of thyme, eucalyptus or other to alleviate breathing congestion.
Fourth; The product object of the present invention fulfills the qualities of absorption of malodor and/or the release of aromas or fragrances in a passive way, when being exposed to the environment in any container that allows its contact with the air around it. The new product can also be used as a substantial component in active systems, since it can be adapted to all type of air conditioning, heating, air filtration, air care, industrial or commercial spaces as well as transportation vehicles. Functionality is mostly dependent on the use of an appropriate container that adapts to the required air intake of the system in question.
The qualities of the new product are more obvious and more effective in active systems of air filtration and conditioning, characterized by recycling air in relatively reduced spaces, such as automobiles, airplanes and public transportation vehicles. The intensity and duration of the aroma or fragrance released in the air through active systems, can be controlled by the concentration of aromas, fragrances or active substances to be used as well as it""s adequate formulation, according to the knowledge available for the state of the art.
The effectiveness and duration of this new product in combination with active systems, will depend on the absorbent agent""s volume and this amount is calculated in direct relationship to the volume and air speed that the active system moves in a given period of time.
The preferred embodiment of the product object of the present invention consists of two basic elements: first, a carrier characterized by its great capacity for odor and malodor absorption, and gradual release of other active substances toward the air or surrounding atmosphere. Second, one or more chemical, natural or synthetic elements that added to the carrier complete diverse functions, according to the desired results (perfume surrounding air, react with undesirable substances present in the air, liberate therapeutic, repellent or attractant chemical agents).
The carrier which is the preferred embodiment of the product in the present invention is a material obtained from the threshed ear of corn (Zea maiz) whose special physical and chemical qualities allow the previously described functions, of absorption and gradual release. To obtain the different components that comprise the threshed ear of corn, an industrial process, well known in the state of the art is required, which consists of separation, classification and sizing of each one of the components that constitute corncobs.
The threshed ear of the corn, also known as xe2x80x9colotexe2x80x9d in Mexico, xe2x80x9cspiga de maizxe2x80x9d in Castilian, corncob in English, xe2x80x9csabugoxe2x80x9d in Portuguese and xe2x80x9cballe de maisxe2x80x9d in French, if cut transversely is constituted by three concentric ring. Starting with the inner ring, they are known in English as pith, woody ring and chaff. The material of the present invention uses the woody ring and chaff portions.
The woody ring, as well as the chaff portions have similar characteristics, both can be used as carriers for active ingredients as described in the body of the present invention. The main differences reside in the difference of absorption capacity and in the particle hardness. Other differences exist and are described below.
In order for the woody ring to comply with the requirements of the present invention it must have the following characteristics: woody ring should be 99% free of other cob particles, it should have no more than 1% dust or fines (the product should be air washed). It must be subjected to heat treatment that guarantees microbiology content and moisture levels under 10%. For correct functionality, the particle size should be uniform in size and ranges should not exceed a maximum of 2380 microns and a minimum of 250 microns.
The woody ring of corncobs is characterized by the following: a hardness of 4.5 on the Mohs scale, a fast absorbency of oil (for example soybean oil) of 1 to 1 on weight basis and the typical molecular structure of a natural fiber. Ideally particle sizing for the present invention should be between the following ranges: 1) retained or larger than a mesh of 2380 microns, 2) particles between 2380 and 1191 microns, 3) particles between 1191 and 841 microns, 4) particles between 841 and 420 microns.
The main characteristic of the particle size is the surface area that each one represents; for example, particles between 1410 and 841 microns have an average surface area of 5.88 square meters per gram. Particles between 841 and 420 microns have an average surface area of 7.20 square meters per gram. This characteristic is decisive in the qualities of absorption of different substances on the part of the carrier that embodies the product object of the present invention.
It is necessary to highlight that woody ring particles are characterized by having a structure that seen on an electron microscope, resembles that of a sea sponge. One can infer that this type structure has capacity to admit and retain substances of small and large molecular size. This allows superior qualities of absorption in comparison to other products such as Cyclodextrin that as is known in the state of the art, only admits malodor molecules of small size.
The separate and classified sizes of woody ring have unique qualities for the absorption of scents from the air in contact with them. To illustrate this, diverse laboratory tests were made with surprising results as follows: